Imbrium Therapeutics L.P. and SpineThera, Inc. Announce First Patient Dosed in Phase 1/2 Clinical Study

Imbrium Therapeutics L.P., a clinical-stage biopharmaceutical company and operating subsidiary of Purdue Pharma L.P., in conjunction with SpineThera, Inc., today announced the first dose administered in the SALIENT (Safety and Efficacy of SX600 Administered by Lumbosacral Transforaminal Epidural Injection for Radicular Pain) Phase 1/2 clinical study of SX600, a non-opioid epidural steroid injection in development for the treatment of sciatica. The companies previously announced that Purdue Pharma L.P. and SpineThera, Inc., had entered into an agreement that provides Purdue the exclusive option to acquire SpineThera, Inc. and gain worldwide rights to its products and technology platforms, including lead asset SX600.

"The first patient dosed with SX600 is an exciting moment in the investigation of this novel, sustained-release, injectable, micro-suspension corticosteroid, and brings us closer to our goal of addressing the unique requirements of an epidural injection to treat back pain," said Paul Medeiros, president of Imbrium Therapeutics. "This is an important milestone as we seek to understand the capabilities of SX600, in treating this potentially debilitating condition¹."

Jeff Missling, founder and CEO, SpineThera, added, "The first patient dosed in the SALIENT Phase 1/2 clinical study represents an important step in the development of this innovative medication, which, if approved by the FDA, could represent the first and only steroid injection indicated for epidural administration."

SALIENT is a double-blind, randomized, placebo-controlled, parallel-group, first-in-human study evaluating the efficacy and safety of two doses (12.5 mg and 25 mg) of SX600 as a sustained-release, injectable treatment option for pain in and near the spine.

"Most people will experience a form of low back pain, such as sciatica, at some point in their lifetime, and it is the most common cause of job-related disability, as well a leading contributor to missed work days.² With the SALIENT clinical study, we seek to explore new options for patients with sciatica," said Craig Landau, MD, president and CEO, Purdue Pharma L.P. "The SX600 clinical development program aligns with Imbrium's focus to rapidly advance the development of non-opioid alternatives to treat pain."

To learn more about the study, please visit clinicaltrials.gov.

This release discusses an investigational agent under development. It is not intended to convey conclusions about efficacy or safety, and there is no guarantee that it will successfully complete clinical development or gain FDA approval.

About Imbrium Therapeutics L.P.

Imbrium is a clinical-stage biopharmaceutical company dedicated to advancing medical science through the development of important new pharmacologic and biologic therapeutics. We are pursuing non-opioid approaches to the management of pain, oncology chemotherapeutics, and treatments for disorders of the central nervous system. As an operating subsidiary of Purdue Pharma L.P., Imbrium strives to develop and bring to market new medicines that serve the unmet needs of patients, physicians and health systems worldwide. We have built a robust and diversified pipeline of investigational drug candidates, and we actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit www.imbriumthera.com.

About SpineThera

SpineThera designs and develops sustained-release, injectable drugs to meet the unique safety requirements for administration in and near the spine. Our goal is to develop proprietary drugs that offer patients and physicians new treatment options that reduce risk, improve outcomes, and manage overall treatment costs in markets with few or no approved drugs. SX600, our lead product candidate, is an investigational drug. SpineThera Australia Pty Ltd is a wholly owned subsidiary of SpineThera, Inc., and is the sponsor of the SALIENT study.

¹ American Association of Neurological Surgeons. Low Back Pain. August 2019. Accessed Sept 4, 2019. Retrieved from https://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Low-Back-Pain.
² National Institute of Neurological Disorders and Stroke. Low Back Pain Fact Sheet. August 2019. Accessed Aug 29, 2019. Retrieved from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Low-Back-Pain-Fact-Sheet#3102_10.